In some hair transplant techniques, including for example micro graft hair transplant techniques, individual follicular units of hair are harvested from a donor region for micro graft transplantation in a recipient region. Follicular unit hair transplantation systems are described, for example, in U.S. Pat. No. 6,572,625 (Rassman), U.S. Pat. No. 5,989,279 (Rassman) and U.S. Pat. No. 5,782,851 (Rassman). Follicular units may be harvested by first removing a section or strip of skin from an area where hair grows. This donor section may then be further dissected and/or sliverized into smaller strips or sections and finally into individual follicular units. A follicular unit is a natural grouping of hairs, from 1 hair up to 4 hairs, most commonly 2 or 3 hairs, which grow together as a group, including a common root sac. The size of individual follicular units may depends on factors including the number of hairs in the follicular unit and the thickness of the individual hairs, with an exemplary range of about 2 um to 4.5 um.
The donor sections or sliverized sections may be viewed under a microscope to identify follicular units for dissection and subsequent transplantation. Magnification of the donor sections make the individual follicular units visible, which may permit a technician to dissect individual follicular units fordissection. If the follicular units are not visualized during dissection, some of the follicular units could be damaged or missed during dissection, thereby reducing the yield from the donor section in terms of the number of transplantable follicular units available for dissection from a given donor section.
In certain donor sections or strips, for example, it may be difficult to distinguish some hairs. Lighter colored hairs may be particularly susceptible to being overlooked or not clearly viewed during dissection. The root sac may also be overlooked or not clearly viewed due to glare or reflected light. As a result, some of the follicular units and/or root sacs in the donor section may not be sufficiently defined or visible in the magnified image of the donor section and may be overlooked and/or damaged during dissection. Overlooking or damaging otherwise transplantable follicular units reduces the number of hairs or follicular units that can be harvested for transplantation from a given donor section.